Elevated Temperature Fatigue Behavior of Tungsten Fiber Reinforced Superalloy Composites

Elevated Temperature Fatigue Behavior of Tungsten Fiber Reinforced Superalloy Composites PDF Author: JL. Yuen
Publisher:
ISBN:
Category : Automotive medicine
Languages : en
Pages : 9

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Book Description
The low-and high-cycle fatigue behavior of three different fiber-reinforced superalloy (FRS) composite materials were evaluated. Each composite material contained 40 vol% unidirectionally aligned continuous length tungsten-1.5 wt% ThO2 fibers. The metal matrices were Waspaloy, Type 316L stainless steel, and Incology 907. Fatigue tests were conducted at 871°C in a helium atmosphere under load control with a load ratio (minimum stress/maximum stress) of 0.2. The composites were found to have excellent elevated temperature fatigue strength. The fibers played a major role in controlling the fatigue strength of the composites. Fatigue crack fronts were found to be retarded by the fibers. The cracks tended to branch at the fiber/matrix interface and grew by a sliding mode along the interface. Matrix surface cracks induced by thermal shock damage had little influence on the fatigue strength of the FRS composites.

Elevated Temperature Fatigue Behavior of Tungsten Fiber Reinforced Superalloy Composites

Elevated Temperature Fatigue Behavior of Tungsten Fiber Reinforced Superalloy Composites PDF Author: JL. Yuen
Publisher:
ISBN:
Category : Automotive medicine
Languages : en
Pages : 9

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Book Description
The low-and high-cycle fatigue behavior of three different fiber-reinforced superalloy (FRS) composite materials were evaluated. Each composite material contained 40 vol% unidirectionally aligned continuous length tungsten-1.5 wt% ThO2 fibers. The metal matrices were Waspaloy, Type 316L stainless steel, and Incology 907. Fatigue tests were conducted at 871°C in a helium atmosphere under load control with a load ratio (minimum stress/maximum stress) of 0.2. The composites were found to have excellent elevated temperature fatigue strength. The fibers played a major role in controlling the fatigue strength of the composites. Fatigue crack fronts were found to be retarded by the fibers. The cracks tended to branch at the fiber/matrix interface and grew by a sliding mode along the interface. Matrix surface cracks induced by thermal shock damage had little influence on the fatigue strength of the FRS composites.

High Temperature Fatigue Behavior of Tungsten Copper Composites

High Temperature Fatigue Behavior of Tungsten Copper Composites PDF Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781792754432
Category : Science
Languages : en
Pages : 36

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Book Description
The high temperature fatigue behavior of a 9 vol percent, tungsten fiber reinforced copper matrix composite was investigated. Load-controlled isothermal fatigue experiments at 260 and 560 C and thermomechanical fatigue (TMF) experiments, both in phase and out of phase between 260 and 560 C, were performed. The stress-strain response displayed considerable inelasticity under all conditions. Also, strain ratcheting was observed during all the fatigue experiments. For the isothermal fatigue and in-phase TMF tests, the ratcheting was always in a tensile direction, continuing until failure. The ratcheting during the out-of-phase TMF test shifted from a tensile direction to a compressive direction. This behavior was thought to be associated with the observed bulging and the extensive cracking of the out-of-phase specimen. For all cases, the fatigue lives were found to be controlled by damage to the copper matrix. Grain boundary cavitation was the dominant damage mechanism of the matrix. On a stress basis, TMF loading reduced lives substantially, relative to isothermal cycling. In-phase cycling resulted in the shortest lives, and isothermal fatigue at 260 C, the longest. Verrilli, Michael J. and Kim, Yong-Suk and Gabb, Timothy P. Glenn Research Center NASA-TM-102404, E-5156, NAS 1.15:102404 RTOP 510-01-0A...

High-Temperature Tension-Compression Fatigue Behavior of a Unidirectional Tungsten Copper Composite

High-Temperature Tension-Compression Fatigue Behavior of a Unidirectional Tungsten Copper Composite PDF Author: MJ. Verrilli
Publisher:
ISBN:
Category : Composite materials
Languages : en
Pages : 12

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Book Description
The high-temperature fatigue behavior of a [0]12 tungsten fiber-reinforced copper matrix composite was investigated. Specimens having fiber volume percentages of 10 and 36 were fatigued under fully reversed, strain-controlled conditions at both 260 and 560°C. The fatigue life was found to be independent of fiber volume fraction because fatigue damage preferentially occurred in the matrix. Also, the composite fatigue lives were shorter at 560°C as compared to 260°C, due to changes in mode of matrix failure. On a total strain basis, the fatigue life of the composite at 560°C was the same as the life of unreinforced copper, indicating that the presence of the fibers did not degrade the fatigue resistance of the copper matrix in this composite system. Comparison of strain-controlled fatigue data to previously generated load-controlled data revealed that the strain-controlled fatigue lives were longer because of mean strain and mean stress effects.

High Temperature Fatigue Behavior of Tungsten Copper Composites

High Temperature Fatigue Behavior of Tungsten Copper Composites PDF Author: Michael J. Verrilli
Publisher:
ISBN:
Category : Metallic composites
Languages : en
Pages : 16

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NASA Technical Memorandum

NASA Technical Memorandum PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 492

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A Preliminary Characterization of the Tensile and Fatigue Behavior of Tungsten-fiber/Waspaloy-matrix Composite

A Preliminary Characterization of the Tensile and Fatigue Behavior of Tungsten-fiber/Waspaloy-matrix Composite PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 22

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High Temperature Tension-compression Fatigue Behavior of a Tungsten Copper Composite

High Temperature Tension-compression Fatigue Behavior of a Tungsten Copper Composite PDF Author: Michael J. Verrilli
Publisher:
ISBN:
Category : Compressibility
Languages : en
Pages : 0

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Book Description


Scientific and Technical Aerospace Reports

Scientific and Technical Aerospace Reports PDF Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 1102

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Thermomechanical Fatigue Behavior of Materials

Thermomechanical Fatigue Behavior of Materials PDF Author: Michael A. McGaw
Publisher: ASTM International
ISBN: 0803134673
Category : Alloys
Languages : en
Pages : 330

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Book Description
"ASTM Stock Number: STP1428. - "Fourth Symposium on Thermomechanical Fatigue Behavior of Materials, held in Dallas, Texas on November 7-8, 2001. The Symposium was sponsored by ASTM Committee E08 on Fatigue and Fracture and its Subcommittee E08.05 on Cyclic Deformation and Fat. - Includes bibliographical references and indexes. ASTM International; 2011.

Elevated-temperature Tensile Properties of Alloyed Tungsten Fiber Composites

Elevated-temperature Tensile Properties of Alloyed Tungsten Fiber Composites PDF Author: Donald W. Petrasek
Publisher:
ISBN:
Category : Metals
Languages : en
Pages : 36

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Book Description
The effects of selected alloying elements on the elevated temperature tensile properties of tungsten fiber reinforced composites were studied. Composites were made of copper, copper- 2 percent chromium and copper- 10 percent nickel reinforced with various volume percents of uniaxially oriented tungsten fibers. The composites were tested in tension at temperatures up to 1800 degrees F.A comparison of the elevated-temperature tensile properties of tungsten fiber - copper alloy composites, representing soluble systems, was made with tungsten fiber - copper composites, representing a mutually insoluble system. The effects of alloying on the elevated-temperature tensile properties of tungsten fiber reinforced composites was also studied. A linear relation existed at elevated temperatures between tensile strength and volume percent fiber content for all the systems investigated. The copper alloy composites were weaker in tension at high volume percent fiber contents than copper composites in which alloying with the fiber did not occur. The tensile strength of the alloyed tungsten fiber decreased with increasing penetration of the alloying element into the tungsten fiber.